Separator for self-priming pumps or the like



June 27, 1939. LA BOUR SEPARATOR FOR SELF-PRIMING PUMPS on THE LIKEFiled Nov. 5, 1957 3 sheetsv-sheet 1 June 27, 1939. H. E. LA BOURSEPARATOR FOR SELF-PRIMING PU MP OR Til! LIKE Filed Nov. 5, 1957 --sSheets-Sheet 2 m 21, 1939. H. E. LA BOLIR 2,163,951

SEPARATOR FOR SELF-PRIMING'PUMPS on THELIKB 'Filed .Nov 5, 19:57 f sSheets-Sheet 3 casing.

leases June'27, was

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s'EPARA'roit FOR SELFJ-PRIMING PUMPS on THE HarryE. La. Bout, Elkhart,Ind. Application November 5, 1937, SerialNo. 172,945

' 6 Claims.

-My invention relates to centrifugal self-prim: ing pumps and isparticularly concerned with the means for releasing the. gas entrainedin the charge of workingliquid during priming.

Self-priming centrifugal pumps usually provide in their structure, orassociated structure, means for retaining a charge of working liquidwhich is employed as a medium for withdrawing air or other gas or vaporfrom the suction line in suffieient amounts to cause the liquid to riseinto the pump.

This charge of liquid, during priming, is involved in three importantfunctions. First, it is charged with air to form a working fluid ormixture Within the pump casing. This fluid or mix.-

ture has sufficient density to develop the necessary discharge pressurerequired to permit carrying out of the air in the pump casing and thesuction pipe against at least atmospheric pressure, or whatever head thepump may be working against. Second, the charge Of liquid provides apool or body which serves as a reservoir to which the stream ofdischarged mixture is added and from which the stream of return orpriming liquid is withdrawn. Third, the body or pool of liquid permitsof the separation of-the entrained gas whereby the gas is rejected oreliminated. Additionally, this body or pool or" liquid serves as aliquid seal, preventing the entry of air or other gas into theinteriorof the pump The effectiveness of the priming action de-- pends upon thebalanced relation of the various actions above enumerated. The mixing ofthe liquid with gas in the pump casing is effected by the rapidlyrotating impeller and is rather easily attained because of thepositiveeffeet of the impeller. I The separation of the gas from theliquid is usually carried on in a chamber known as a separator, which,during priming, retains the charge or pool of liquid above referred to.If

all gas could ,be eliminated from the return or priming liquid the rateof priming would be greatly enhanced. In fact, the chief practicalobstacle to effectiveness in priming is the difficulty of eliminatingthe entrained gas from the liquid which is returned to the pump casing.

-This is apparent from the fact that any en the return passageway.However, the greater the volume of liquid required to be maintained inthe separator, the more diiii'cult it is to secure rapid elimination ofthe entrained gas. In the early form, of pump shown in Patent 5 No.1,578,236 and wherein the separator is'disposed above the pump, gravityseparation, i. e., rise of the entrained air by difference in gravity tothe releasing surface of the liquid, was chiefly relied upon. j i 1o Forcertain situations, such as low head mine work, the top type separatorrequired too great head room, and I thendeveloped the side typeseparator, as disclosed in myPatent No. 1,908,635.

In this typev of separator theliquid in the 'sepa-' 16 rator was causedto whirl on a vertical axis by 'ing priming, I. have devoted much studytdthe provision of separators for various designs of pumps, and callattention to separators shown in the following patents issuedto me:

In Patents Nos. 1,915,678 and 2,019,143 Zapplied the principle ofseparation by centrifugal action in a top type separator, the whirloccurring on a horizontal axis and lying in substam tially a verticalplane. i

In Patent No. 1,966,896 I combine the action 013 5 centrifugalseparation with gravity separationin a separator surrounding the pumpcasing.

In Patent No. 2,005,466 I employed a helical travel of the mixture on 2.horizontal axis, supplementing the same with gravityseparation in adistinct and separate part of the separator.

While these various forms of separator and their separating actiongave'better separation at least for certain purposes, it is to beobserved that they became more complex and more expensive to construct.i

The object ofthe present invention is to provide a separator of simple,inexpensive construetion and 01' good emciency. The present separator isthe first to take an entering vertical iiow of mixture, spread it out ina relatively thin stream moving in a horizontal whirl on the innercylindrical walls, and then more or less retarding or stopping the whirlenough to insure sealing the outlet and causing the liquid to flow down55 and out of the separator in a substantially vertical direction.

A further object is to teach a method of separating gas from liquid in aseparator particularly adapted for centrifugal pumps of the selfprimingclass.

A further object is to provide a top type separator for pumps of theclass herein referred to, applicable to pumps of present construction toimprove the effectiveness of pumps of this class,

both in priming and in liquid pumping.

A further object is to provide a separator, for pumps of the type hereinreferred to. which has the ability to clean itself and avoid cloggingwith entrained solids. Also, this separator tends to prevent the returnof solids from the bottom of the separator into the pump casing duringpriming or backflow which occurs upon stopping the pump.

Other and incidental objects will be apparent from the followingdetailed specification and the appended claims.

Now in order to acquaint those skilled in the art with the manner ofconstructing and operating a specific embodiment of my invention I shalldescribe, in connection with the accompanying drawings, one form inwhich my invention may be embodied.

In the drawings:

Figure 1 is a front elevational view of a separator superimposed upon apart of the pump casing;

Figure 2 is a top plan view of the separator of my invention;

Figure 3 is a side view of the separator taken from the right of Figure1;

Figure 4 is a vertical section taken on the line 4ii of Figure 3;

Figure 5 is a horizontal section taken on the line 55 of Figure 4,looking downwardly; and

Figure 6 is a diagrammatic side elevational view illustrating thecomponent parts of a complete self-priming pump.

In the attainment of the above objects I provide a novel method ofseparation which involves the employment of a body of fluid whirling ona vertical axis to produce inertia separation or centrifugal separation.This vertical whirl is, however, not a free whirlpool, for reasons laterto be explained, but a whirl with a certain amount of breaking orretardation, which has the dual effect of preventing too deep a vortexand also of tending to pile up or gather the liquid at the mouth of thereturn passageways. Thereby the orderly separation and return of primingliquid is assured over a fairly wide variation of operating conditionssuch as speed, density of the liquid, volume of liquid, vacuum attainedduring priming, etc.

Referring first to Figure 6, I have here shown a self-primingcentrifugal pump which comprises the main parts as follows. The pumpcasing i has its inlet at 2 to which there is connected an inlet trap 3having inlet connection 4. The pump casing I has a discharge connection5 which is illustrated in detail in Figure 1 and this dischargeconnection is coupled to the separator 6 which has at its upper end theoutlet connection I. The pump casing I contains a suitable rotor orimpeller provided with vanes 9 which, in this case, sweep the insideperiphery of the channel in which the blades 9 run. The inner peripheryId of the channel, in which the blades 9 run with relatively smallclearance, communicates through two tangential passageways i2 and withoutlet openings at the top or the pump casing where the connection 5 ismade. The passageway i2 is the main discharge passageway and thepassageway I3 is the auxiliary discharge passageway which, during thepriming operation, serves as the return passageway for the primingliquid to maintain the circulation of liquid back into the pump casingfor discharge of the mixture through the main passageway 12.

The casing l and the separator 6 have meeting flanges i4 and 15 forconvenience in construction and assemblage of the parts. Obviously, theseparator may be cast as an integral part of the back plate of thecasing, or the structural arrangements may be otherwise varied withoutdeparting from the present teaching.

The separator 6 comprises, in the form shown, a hollow cylindrical bodyportion providing a separating and discharge chamber. A top outletconnection I may be disposed in any horizontal direction desired. Hereit is shown as facing forward parallel to the axis of the impeller shaft16. The outlet connection 7 comprises a tubular passageway ll formedthrough a neck l8 and herein shown as surrounded by a clamping flange 9for making connection with the discharge pipe of the pump, which may beled to any suitable point, preferably to a point communicating withatmosphere. The top of the separator is provided with a threaded opening2| for filling purposes and this opening 2! is normally closed by ascrew plug shown in dotted lines in Fig. l.

The lower end of the cylindrical body portion of the separator G mergesinto a conical wall 22 and at the central part of the conical section 22is provided the passageway 23 matching with the main dischargepassageway 12 in the pump body. A tubular extension 24 contains a returnpassageway 25 which matches with the auxiliary discharge passageway 83in the pump body. These passageways 23 and 25 form openings through themating flange l5 so that when the flanges it and I5 are clamped togetherthe separator communicates with the interior of the pump casing throughthe main discharge passageway I2, 23 and the auxiliary dischargepassageway i3, 25. Obviously, any of these parts may be formed asseparate pieces joined together for convenience in manufacture andassembly.

Within the separator 6 there is formed an integral inclined vane 27which defines a passageway 28 forming a communication between theopening 23 and the interior of the separator 6. This inclined vane hasits lower edge joined to the conical portion 22 along the curvedintersection 29 indicated in Figs. 2 and 3 in dotted lines. The edge ofthe vane 21 indicated by the intersection of the vane with thecylindrical portion is designated by reference numeral 3%. The free edgeof this vane is indicated by reference numeral 32. This vane may befiat, that is, planar form, or it may be warped, as desired. Itsfunction is to impart a tangential direction to the mixture enteringthrough the central opening 23 under the vane 21. In other words, theliquid discharged through the main discharge passageway l2 entersthrough the opening 23 in the bottom of the separator and is directed bythe vane 21 in a spiral and subsequent helical path around the insideperiphery of the separator 6. Thus the axial entry is directed intotangential travel.

This tangential travel inside of the circular chamber would tend to forma whirlpool with a deep vortex at the center. Depending upon thevelocity of discharge and the quantity of liquid forming the charge ofpriming medium, the vortex might extend down far enough to produce arelatively thin layer of liquid over the opening 33 (see Figure 5) wherethe return passageway 25 opens into the interior of the chamber 6.Hence, under certain conditions, particularly where a relatively highsuction is being created inside the pump casing, a tendency is producedfor the atmospheric pressure suddenly to strike through the relativelythin layer of liquid and travel down through the opening 33, passageways25 and I3, into the interior of the pump casing, destroying the vacuum.The whirling motion of the liquid to free the same of the entrained airis highly desirable, as it performs two useful functions, first, thecentrifugal efiect of forcing the air to the center of the whirlpool andsecond, giving a greater area of free surface from which the gas canescape from the liquid. How-- ever, an: uncontrolled vortex isundesirable for the reasons above stated.

A vertical rib or baflle 34 extends approximately radially from theinner wall of the separator 6 in a vertical direction. This baflle orrib performs two useful functions. The first is to create a region'ofpressure of liquid, by impingement of the liquid stream thereagainst,directly over the opening 33. That is to'say, considering the directionof rotation of liquid charged with air in the separator, the tendency ofthe lighter liquid mixture is to go to the top, and the denser or lessgas-containing liquid to gravitate toward the bottom of the separator,but the tangential motion imparted by the vane 2'! causes both parts ofthe liquid to move in substantially a helical or spiral path. Thismotion of the liquid represents a certain kinetic energy which, byimpingement against the vane fit, is transformed into pressure upon themouth 33. This insures sealing of the opening 33 with liquid and alsoperforms the useful function of putting a braking or amortizing effectupon the otherwise uncontrolled whirling of the liquid. The form of thisvane or baflie 34 may be controlled to produce the desired efliectsabove indicated, or'either of them.

It will be seen in Figure 5, as indicated by the arrow 36, that thespiral and helical flow produces an impingement upon the side of the ribor baille 3d which is adjacent the opening 33, whereby to createpressure at this point. The liquid not so engaging the vane or baflle 34is forced radially inwardly in order to continue its rotary travel. Bythis arrangement a control of the vortex action is secured and even ifthe retained priming liquid is below normal, as sometimes occurs, thepiling up or impingement against the vane 34 and consequent sealing ofthe port 33 is an important aspect of the present invention. Also, itmay be seen that the pump may be designed to prime on a smaller chargeof liquid under these conditions. The operation of the pump, in brief,is as follows:

Assuming that the pump has ceased pumping liquid, and liquid has beenallowed to how back through the connection I, separator 6, pump casmg l,through the trap 3 and back through the suction connection 4 to thepoint of breaking the suction existing at the top of the trap, a

certain charge oi liquid will be retained in the trap and in the pumpcasing. This, as a maximum, is represented by the level an which is thebottom of the suction connection it. As-

suming that auction pipe is sealed with water and that the shaft it isrotated, liquid will be drawn from the intake trap t and dischargedthrough both passageways it and it and driven into the separator 8.Immediately thereafter. since the impeller cannot develop suficientpressure on air alone, liquid will return through the port 33,passageway 25 and it, into engagement with the impeller 8, whereupon amixture of gas and liquid is formed of a density great enough to createa discharge pressure to prevent return of liquid through the passageway52. The pump then continues to circulate the priming liquid, drivingmixture out through the passageway iii and receiving priming liquidtract: through the passageway iii. The stream of discharge minturepasses up through the central passageway 23 in the bottom of theseparator t, under the vane 21, where it is directed in a spiral path asindicated in Figures 4 and 5, giving to the body or pool of liquid inthe chamber ii a whirling motion, the whirl being on a vertical axis.This creates a desirable separating action for separating the gas fromthe liquid, due both to the centrifugal eflect and to the increase ofarea, as well as the thinning of the layer of liquid, that is,- reducingthe distancewhich a bubble of gas must travel inorder to reach a surfacewhere it can free itself. The uncontrolled whirling of the liquid isprevented by the battle tit, which creates aplenum by impact of theliquid upon the port 33. The liquid piles up along the rib or baffle 34and tends to fall into the port 33, where it flows back by way of thepassage way 25, i3 to maintain the circulation of the pump duringpriming. When the priming operation has proceeded to the point ofdrawing liquid from the source. in through the intake trap 3 into thepump chamber l to fill or substantiallyfill the impeller 93, thepressure developed upon the secondary orreturn passage or throat i3 isgreat enough to prevent the re turn how of liquid through this route andliquid is discharged through both it and it into the separating chamberin the separator ii. Due to the action of the vane or bathe 3 in brakingor amortizing the whirl, and due to the outflow of liquidat the port asdistinguished from the previous inflow, a greater iii-airing action oramortization of the whirl is produced by the flow of the secondarypassageway, whereby the losses which otherwise'would occur due to thewhirling action oreddying is reduced when the two throats aredischarging liquid. The vane or battle it may be inclined in a directionopposite to the whirl created by the main discharge stream so that thetwo effects can be caused even more to counteract each other. This is arefinement, and is optional. When the pump thus pumps liquid theseparator t fills with the liquid and discharge occurs at the opening itin the discharge connection i.

Since the member 6 whichI have above termed the separator chamber servesthe dual function of a separator chamber during priming and a means forjoining the two discharges from the throats i2 and it during liquidpumping, it can be seen that it performs an important function in theoperation of a self-priming pump unit. In

other words, the action or the impeller and its casing l. in conjunctionwith the action occurring in the separator 55 during priming and duringliquid pumping, involves an important cooperation, each being influencedby the operation of the other.

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I do not intend to be limited to the specfic details shown anddescribed, as the above specific embodiment is given by way of exampleand illustration, rather than of limitation.

I claim:

1. For use as a part of a self-priming centrifugal pump, a separatorcomprising a tanlclike substantially vertical cylindrical shell having atop outlet to permit the escape of gas during priming and for thedischarge of liquid after priming is completed, a vertical inlet at thelower end of said shell, a vane in said shell for causing the verticallyentering stream of mixture to travel about the inner periphery of theshell in a horizontal loop, an outlet for the fiow of priming liquidfrom the separator back to the pump, and a battle disposed in relationto the latter outlet to cause a piling up of the whirling liquid at saidlatter outlet to seal the same with liquid during priming.

2. A separator and discharge chamber for a self-priming centrifugal pumpcomprising a substantially cylindrical shell having a main outletconnection at its upper end for the discharge of gas during priming andthe discharge of liquid during liquid pumping, said shell being disposedwith its longitudinal axis substantially vertical, inlet means at thelower end of the shell arranged to direct an entering stream of mixtureduring priming substantally tangentially to the inner periphery of saidshell to produce a horizontalswirling of the mixture in the chamber, anaum'liary passageway in the lower end of the chamber and a bafiieadjacent said auxiliary passageway extending in a direction transverseto the direction of swirl of the liquid, said battle being adapted to beengaged by the swirling liquid and thereby causing the liquid to pile upand seal the auxiliary passageway during priming.

3. A separator and discharge chamber having a vertical axis and anoutlet at its upper end, means to discharge a vertically entering streamof mixture of gas and liquid into the separator ber, an outlet forliquidiroin which the gas been separated and a vertically extending va ebehind said outlet with reference to the direct l of motion of theswirling body, said vane being adapted to be impinged by the swirlingbody for creating a liquid seal upon said outlet.

A separator for a centrifugal self-prim pump comprising a shell ofsubstantially cylind cal form arranged with its longitudinal axisveltical, an outlet at the upper end, a main inlet disposedsubstantially axially itt lower on the shell. and a priming outlet 1- ig from peripheral part of the lower ens oi ti means for directing thevertice 'y entel.. of mixture substantially tangenti walls of the shellin a generally ho tion and a ballie disposed in dire c the primingoutlet, said baffle tending to ins sealing of said outlet with liquidand limiting the whirling of the liquid within the separator.

5. The separator of claim 4 wherein the lower end of the shell has aconical portion main inlet disposed at the apex of the cone and whereinthe means for directing the st am of mixture comprises a vane extendingfrom the conical wall to the cylindrical wall of the shell.

6. A separator having a cylindrical shell with a vertical axis, a topoutlet, a mixture inlet lor leading mixture generally vertically intothe shell and having means for directing the same in a thin layerwhirling horizontally on the inner cyindrical walls, a verticallydisposed baffle on the inner wall of the shell and a generallyvertically downwardly directed outlet having an opening into the insideof the shell in front of said bafile with reference to the direction ofmotion of the whirling layer.

its,

"EARRY BO-UR.

